Room temperature terahertz quantum cascade laser sources with 215μW output power through epilayer-down mounting

摘要

We report room temperature terahertz (THz) quantum cascade laser sources with high power based on difference frequency generation. The device is Cerenkov phase matched and spectrally purified with an integrated dual-period distributed-feedback grating. Symmetric current injection and epilayer-down mounting of the device onto a patterned submount are used to improve the electrical uniformity and heat removal, respectively. The epilayer-down mounting also allows for THz anti-reflective coating to enhance the THz outcoupling efficiency. Single mode emission at 3.5 THz with a side-mode suppression ratio and output power up to 30 dB and 215 μW are obtained, respectively.